export default {
    getShader: function () {
        return `
        precision mediump float;
        uniform vec4 u_Color;
        uniform float u_Margin;
        varying float v_Set;
        void main(){
            vec4 color = u_Color;
            float set = v_Set;
    
            float dist = distance(gl_PointCoord, vec2(0.5, 0.5));
            if(dist < u_Margin){
    
                if(set > 0.3){
                    color.a *= 1.0 - (set - 0.3) / 0.3;
                }
    
                gl_FragColor = color;
            }
        }
        `;
    }
}